rfc1866.txt

RFC 的详细文档！

5.5.2.1. Example and Listing: XMP, LISTING

   The <XMP> and <LISTING> elements are similar to the <PRE> element,
   but they have a different syntax. Their content is declared as CDATA,
   which means that no markup except the end-tag open delimiter-in-
   context is recognized (see 9.6 "Delimiter Recognition" of [SGML]).

      NOTE - In a previous draft of the HTML specification, the syntax
      of <XMP> and <LISTING> elements allowed closing tags to be treated
      as data characters, as long as the tag name was not <XMP> or
      <LISTING>, respectively.

   Since CDATA declared content has a number of unfortunate interactions
   with processing techniques and tends to be used and implemented
   inconsistently, HTML documents should not contain <XMP> nor <LISTING>
   elements -- the <PRE> tag is more expressive and more consistently
   supported.

   The <LISTING> element should be rendered so that at least 132
   characters fit on a line. The <XMP> element should be rendered so
   that at least 80 characters fit on a line but is otherwise identical
   to the <LISTING> element.

      NOTE - In a previous draft, HTML included a <PLAINTEXT> element
      that is similar to the <LISTING> element, except that there is no
      closing tag: all characters after the <PLAINTEXT> start-tag are
      data.

5.5.3. Address: ADDRESS

   The <ADDRESS> element contains such information as address, signature
   and authorship, often at the beginning or end of the body of a
   document.

   Typically, the <ADDRESS> element is rendered in an italic typeface
   and may be indented.

   Example of use:

    <ADDRESS>
    Newsletter editor<BR>
    J.R. Brown<BR>
    JimquickPost News, Jimquick, CT 01234<BR>
    Tel [phone]
    </ADDRESS>






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5.5.4. Block Quote: BLOCKQUOTE

   The <BLOCKQUOTE> element contains text quoted from another source.

   A typical rendering might be a slight extra left and right indent,
   and/or italic font. The <BLOCKQUOTE> typically provides space above
   and below the quote.

   Single-font rendition may reflect the quotation style of Internet
   mail by putting a vertical line of graphic characters, such as the
   greater than symbol (>), in the left margin.

   Example of use:

    I think the play ends
    <BLOCKQUOTE>
    <P>Soft you now, the fair Ophelia. Nymph, in thy orisons, be all
    my sins remembered.
    </BLOCKQUOTE>
    but I am not sure.

5.6. List Elements

   HTML includes a number of list elements. They may be used in
   combination; for example, a <OL> may be nested in an <LI> element of
   a <UL>.

   The COMPACT attribute suggests that a compact rendering be used.

5.6.1. Unordered List: UL, LI

   The <UL> represents a list of items -- typically rendered as a
   bulleted list.

   The content of a <UL> element is a sequence of <LI> elements.  For
   example:

    <UL>
    <LI>First list item
    <LI>Second list item
     <p>second paragraph of second item
    <LI>Third list item
    </UL>

5.6.2. Ordered List: OL

   The <OL> element represents an ordered list of items, sorted by
   sequence or order of importance. It is typically rendered as a



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   numbered list.

   The content of a <OL> element is a sequence of <LI> elements.  For
   example:

    <OL>
    <LI>Click the Web button to open URI window.
    <LI>Enter the URI number in the text field of the Open URI
    window. The Web document you specified is displayed.
      <ol>
       <li>substep 1
       <li>substep 2
      </ol>
    <LI>Click highlighted text to move from one link to another.
    </OL>

5.6.3. Directory List: DIR

   The <DIR> element is similar to the <UL> element. It represents a
   list of short items, typically up to 20 characters each. Items in a
   directory list may be arranged in columns, typically 24 characters
   wide.

   The content of a <DIR> element is a sequence of <LI> elements.
   Nested block elements are not allowed in the content of <DIR>
   elements. For example:

    <DIR>
    <LI>A-H<LI>I-M
    <LI>M-R<LI>S-Z
    </DIR>

5.6.4. Menu List: MENU

   The <MENU> element is a list of items with typically one line per
   item. The menu list style is typically more compact than the style of
   an unordered list.

   The content of a <MENU> element is a sequence of <LI> elements.
   Nested block elements are not allowed in the content of <MENU>
   elements. For example:

    <MENU>
    <LI>First item in the list.
    <LI>Second item in the list.
    <LI>Third item in the list.
    </MENU>




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5.6.5. Definition List: DL, DT, DD

   A definition list is a list of terms and corresponding definitions.
   Definition lists are typically formatted with the term flush-left and
   the definition, formatted paragraph style, indented after the term.

   The content of a <DL> element is a sequence of <DT> elements and/or
   <DD> elements, usually in pairs. Multiple <DT> may be paired with a
   single <DD> element. Documents should not contain multiple
   consecutive <DD> elements.

   Example of use:

    <DL>
    <DT>Term<DD>This is the definition of the first term.
    <DT>Term<DD>This is the definition of the second term.
    </DL>

   If the DT term does not fit in the DT column (typically one third of
   the display area), it may be extended across the page with the DD
   section moved to the next line, or it may be wrapped onto successive
   lines of the left hand column.

   The optional COMPACT attribute suggests that a compact rendering be
   used, because the list items are small and/or the entire list is
   large.

   Unless the COMPACT attribute is present, an HTML user agent may leave
   white space between successive DT, DD pairs. The COMPACT attribute
   may also reduce the width of the left-hand (DT) column.

    <DL COMPACT>
    <DT>Term<DD>This is the first definition in compact format.
    <DT>Term<DD>This is the second definition in compact format.
    </DL>

5.7. Phrase Markup

   Phrases may be marked up according to idiomatic usage, typographic
   appearance, or for use as hyperlink anchors.

   User agents must render highlighted phrases distinctly from plain
   text. Additionally, <EM> content must be rendered as distinct from
   <STRONG> content, and <B> content must rendered as distinct from <I>
   content.

   Phrase elements may be nested within the content of other phrase
   elements; however, HTML user agents may render nested phrase elements



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   indistinctly from non-nested elements:

   plain <B>bold <I>italic</I></B> may be rendered
   the same as plain <B>bold </B><I>italic</I>

5.7.1. Idiomatic Elements

   Phrases may be marked up to indicate certain idioms.

      NOTE - User agents may support the <DFN> element, not included in
      this specification, as it has been deployed to some extent. It is
      used to indicate the defining instance of a term, and it is
      typically rendered in italic or bold italic.

5.7.1.1. Citation: CITE

      The <CITE> element is used to indicate the title of a book or
      other citation. It is typically rendered as italics. For example:

      He just couldn't get enough of <cite>The Grapes of Wrath</cite>.

5.7.1.2. Code: CODE

      The <CODE> element indicates an example of code, typically
      rendered in a mono-spaced font. The <CODE> element is intended for
      short words or phrases of code; the <PRE> block structuring
      element (5.5.2, "Preformatted Text: PRE") is more appropriate
       for multiple-line listings. For example:

      The expression <code>x += 1</code>
      is short for <code>x = x + 1</code>.

5.7.1.3. Emphasis: EM

      The <EM> element indicates an emphasized phrase, typically
      rendered as italics. For example:

      A singular subject <em>always</em> takes a singular verb.

5.7.1.4. Keyboard: KBD

      The <KBD> element indicates text typed by a user, typically
      rendered in a mono-spaced font. This is commonly used in
      instruction manuals. For example:

      Enter <kbd>FIND IT</kbd> to search the database.





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5.7.1.5. Sample: SAMP

      The <SAMP> element indicates a sequence of literal characters,
      typically rendered in a mono-spaced font. For example:

      The only word containing the letters <samp>mt</samp> is dreamt.

5.7.1.6. Strong Emphasis: STRONG

      The <STRONG> element indicates strong emphasis, typically rendered
      in bold. For example:

      <strong>STOP</strong>, or I'll say "<strong>STOP</strong>" again!

5.7.1.7. Variable: VAR

      The <VAR> element indicates a placeholder variable, typically
      rendered as italic. For example:

      Type <SAMP>html-check <VAR>file</VAR> | more</SAMP>
      to check <VAR>file</VAR> for markup errors.

5.7.2. Typographic Elements

      Typographic elements are used to specify the format of marked
      text.

      Typical renderings for idiomatic elements may vary between user
      agents. If a specific rendering is necessary -- for example, when
      referring to a specific text attribute as in "The italic parts are
      mandatory" -- a typographic element can be used to ensure that the
      intended typography is used where possible.

      NOTE - User agents may support some typographic elements not
      included in this specification, as they have been deployed to some
      extent. The <STRIKE> element indicates horizontal line through the
      characters, and the <U> element indicates an underline.

5.7.2.1. Bold: B

   The <B> element indicates bold text. Where bold typography is
   unavailable, an alternative representation may be used.

5.7.2.2. Italic: I

   The <I> element indicates italic text. Where italic typography is
   unavailable, an alternative representation may be used.




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5.7.2.3. Teletype: TT

   The <TT> element indicates teletype (monospaced )text. Where a
   teletype font is unavailable, an alternative representation may be
   used.

5.7.3. Anchor: A

   The <A> element indicates a hyperlink anchor (see 7, "Hyperlinks").
   At least one of the NAME and HREF attributes should be present.
   Attributes of the <A> element:

    HREF
            gives the URI of the head anchor of a hyperlink.

    NAME
            gives the name of the anchor, and makes it available as
            a head of a hyperlink.

    TITLE
            suggests a title for the destination resource --
            advisory only. The TITLE attribute may be used:

                * for display prior to accessing the destination
                resource, for example, as a margin